<tr>
    <td valign="top">
        <div class="" id="div_file"  style="display: none;">
            <label for="">上传应用：</label>
            <input type="file" class="file" id="file_app" name="file_app" accept=".apk,.ipa">
            <a id="bt_upload_back" class="btn btn-success btn-sm" style="margin-top:10px;width: 80px;">返回</a>
        </div>
    </td>
</tr>
